Method and apparatus for producing collapsible paperboard bodies for tubular containers



vMaly 22, 1945.

2 Sheets-Sheet 1 PAPERBOARD'BODIES FOR TUBULAR CONTAINERS METHOD AND APPARATUS FOR PRODUCING COLLAPSIBLE 4 InvenQr.' R Hurry A.\Nunsker l by/ea/wl/f H Ays.

JEM-mf May 22, 1945.

H. A. WANSKER METHOD AND APPARATUS FOR IRODUCING COLLAPSIBLE PAPERBOARD BODIES FOR TUBULAR CONTAINERS Filed Oct. 22. 1941' 2 Sheets-Sheet 2 y F194. y H

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`Patented May 22, 1945 METHOD AND APPARATUS FOR PRODUC- ING COLLAPSIBLE PAPERBOARD BODIES f FOR `TUBULAB.` CONTAINERS Harry A. wansker, Newtonvme, Mass.

, Application October 22, 194l1, Serial No. 416,004

13 Claims.

This invention relates to methods and apparatus for forming collapsible tubular paperboard bodies of knockdown containers 'of the type in which the tubular body of the container is maintained in expanded formby a rigid flat bottom vinserted into the tubular body within'the end portion thereof with a rigid retaining an d reenforcing member or ring fitting the end of the body and clamping the body tightly against the periphery of the bottom. I

When usual containers of this type are dis.- assembled for storage or shipment the bodies are collapsed, piled one upon the other, and enclosed in a carton or bound to form a convenient4 pack- The bottoms, covers, and rings are similarly packaged in superimposed fiat positions. The paperboard bodies of containers of this type heretofore made have usually beenv rendered circumferentially exible by equally spaced score lines extending longitudinally of the body which are cut through one ofthe surface zones lof the body thereby materially weakening the wall of the body. In other instances flexibilityv is produced by embossing equally spaced parallel lines into the body longitudinally thereof, but in such instances the inner and outer faces of the body present parallel lgrooves and complementary corrugations the formation of which breaks down to a considerable extent the libres of the body wall.

The present invention comprises a method and apparatus for use in forming a collapsible papert board body for containers of this type in'which the body is rendered pliable by impregnation of moisture from dry steam into the surface zones of' the body, with thin lines extending longitudithe body and enabling the retaining ring most closely to t the surface of the, end of the body throughout the circumference thereof.

The present invention comprises a continuation in part of applicants prior application Seof the moistened surface zones of the sheet with..

out breaking the fibres thereof, and sufllciently stretching the fibres of such zone to Aenable the .f

` sheet to be bent into tubular form when dry,

cutting the sheet into sections of suitable length, and securing together the ends of the section.

In assembling the lower end of the tubular body of the sheet within the retaining ring the body is collapsed and a section thereof fitted into a portion of the ring and the body` thenexpanded to. engage the remainder of the ring.- In assembling usual constructions having equally spaced score lines, or equally spaced corrugations, considerable dilculty is experienced in expanding the body into engagement with the ring. The present invention comprises a process of so spacing the indented lines in the surface of the body as will enable the collapsed body of the container, when a section of it is tted within a portion of the ring, to be gradually extended by a sweeping movement of the hand of the operator into the remainder of the ring without dii'-l ficulty. The method comprises indenting successive sections of the moistened sheet with thin parallel lines with the spacing of the lines gradually increasing in width throughout one quarter u section of the sheet, then correspondingly decreasing in width throughout th'e next quarter section, then correspondingly increasing in width throughout the next'quarter section, and correspondingly decreasing in width in the last quarter section, and severing the successive sections from the sheet, and securing together theend panels of the section defined by the most narrowly spaced lines.

The invention also comprises the method for forming collapsible,` bodies of a tubular knockdown container for. use with ice cream of different flavors in which the container is provided with non-obliterable means for identifying the flavor or character of the contents of the container which comprises printing upon the sheet rial Number 375,238, led January 2l, 1941, and

which has matured into Patent No. 2,304,615.

The method comprises broadly moving the sheet of paperboard progressively lengthwise through a surrounding circulating volume of steam thereby moistening and softening the surface zonesof the sheet with moisture to render vthe sheet pliable, then indenting thin parallel lines into one a design in suitable colori to-identify the contents of the container including narrowly spaced parallel lines extending longitudinally of the sheet and indenting the lines sufficiently linto the surface zone of the sheet to render the sheet flexible and to prevent the indented printed portions of the lines from obliteration by abrasion of the surface of the container by handling or othery l of printing a sheet of paperboard, then subjecting the sheet progressively to an enclosed volume of steam, then impressing suitably spaced thin transverse parallel lines intothe sheet in the manner above described and longitudinally scor-l avasas ing the sheet to form external end rib sections for the container; iFig. 2 is a vertical longitudinal sectional view of an insulated steam chamber provided with means for projecting fa substantially uniform current of steam in a streamlined path against the surface of the traveling sheet of material, and heating means' to prevent condensation of the steam, and illustrating diagrammatically means for supplying low pressure dry steam to the steam to be folded against the outer face of the sheet, as illustrated in dotted lines Fig. 5.

Paperboard sheets suitable for bodies of tubular containers for ice cream, and other materials, are-usually of laminated construction having an outer surface zone in which the fibres are more dense than those of the body of the sheetand lwhich frequently are calendered' tovpresent a projecting means and for supplying steam at high pressure to the heating means;

Fig. 3 is a sectional view on line 3--3 Fig. 1,l

viewed upwardly as indicated by-the arrows in Fig.1:

Fig. 4 is a plan view of a section of the sheet sufiicient to form a container body impressed with thin lines extending transversely of the sheet, illustrating notches at the ends of the fold lines,

and showing in dotted lines longitudinal scoring adjacent the edge of the sheet to permit the scored end sections to be folded upon a sheet to form external end ribs for the container body;

entrally broken away showing the scored edge ortions in full lines and in dotted lines the posi- I `tion of the ribs' when folded against the outer surface of the sheet;` and,

Fig. 6 is a view of a collapsed container illustrating ornamentation thereon and means for identifying the contents of the container.

. The `mechanism for producing the successive steps in the process forming the `subject matter of the invention, which is conventionally illusrtrated inFig. 1, shows a roll of paperboard I rotatably mounted upon a suitable arbor lwith the .Y free end of the sheet extending from the roll bechamber 6 containing means for projecting upony one surface zone of the sheet a current of ylow 'pressure substantially dry steam of the full width of the sheet in a streamlined path in the direction of movement of the sheet to enable the surface zones of the sheet to absorb sumcient moisture to render the fibres thereof pliable and to cause the moisture to heat the ink which has been deposited upon the surface of the sheet and cause it to penetrate more deeply into the sheet and to prepare it for rapid drying as soon as the printed matter .progressively emerges from the steam chamber. The sheet thereupon passes immediately from the steam chamber between a pair of complementary rolls 1 and 8 the uppermost of which is provided with suitably spaced thin blades 9 extending longitudinally of theroll for impressing thin lines into the sheet, and also may .be

, provided at itsends with cutting disks to trim and notch the edges of the sheet, while the lower roll 8 is provided` with slight depressions complementary to the blades of'tle cylinder 1 and adjacent or near its ends with scoring disks Ill adapted to score the sheet from beneath sufeiently to provide rib sections II (Fig. 4) adapted Fig.4 5 is an enlarged sectional view of the sheet' smooth surface. AAs a consequence, such surface zone will absorb moisture more slowly than the body of the sheet. One of the principal objects of the present invention is to subject the pref erably denser surface zone of the sheet which is to be stretched when the sheet is bent to' tubular lform with vaporized moisture from a current of dry steam flowing in a streamlined path inthe direction of movement of the sheet and which `will follow the' sheet as it emerges from the steam chamber suiliciently to maintain the surface zone sumciently moist when it is engaged by the means for impressing thin lines transversely of the sheet to avoid breakage of the fibres of Athe surface zone, so that when the sheet is dried and thereafter bent to tubular form the container will have `a continuous unbroken surface.

In the preferred form'of apparatus illustrated herein the steam chamber 6 comprises a rec-l tangular metal casing I2 vwhich is covered pref` erably'on the outside with a layer of insulation I3. ,-Suitably mounted within the steam chamber 6 are metallic headers Il and I5 which extend longitudinally of the chamber near the sides thereof and may be supported in any suitable manner (not shown).

l The headers may be constructed of suitable cast metal cored to provide an outer steam passage I6 for lowpressure steam and a parallel inner passage I1 for heating steam of relatively higher pressure.

A plurality of metal steam delivery ypipes I8 which are welded or otherwise secured at their respective ends to the headers I 4 and I5, com- `municate` with the passage I6. Metal heating pipes I9, which likewise have their ends welded or otherwise secured to the headers I4 and Iii, e125` to the pipes I8 and are preferably located slightly extend in parallelism with and in close proximity in advance of the pipes I8. Desirably solid or tubular bars of heat-conducting metal 20 are interposed between the pipes I8 and I9 for the purpose of conducting heat from the heating pipes I 9 to the steam delivery pipes I8.

The lower portions of the steam delivery pipes I8 are provided with suitable outlets, such as perforations 2,I, so located as to project currents of steam in a downwardly and in a streamlined path upon the traveling sheet I of paperboard the full width thereof. Preferably, as illustrated in the drawings, the perforations 2| in the steam I delivery pipes 20 are so located as to project the steam downwardly along the heating bars 20 against the surface of the steam pipes 20 in such manner as to cause the currents of air to be directed in the streamlined path, as above described.

The exit opening 22 through which the web of paperboard I passes fromthe steam chamber 6 .desirably is somewhat larger than the inlet open-v 1 ing 23 through which the paperboard enters the and indent the parallel lines in the surface zone steam chamber so that the'steam will follow the web of paperboard as it passes'toward the comv l,

plementary rolls 1 andk 8 the blades of which press of the sheet. I

Steam may be supplied to the steam ldelivery pipes and .to the heating pipes in the steam cham- `Jbliteration as will obscure the lines is prevented ber from the same source, such for example as from a steam boiler which generates and maintains the steam atapproximately one hundred twenty-five pounds per square inch; In such case, however, suitable means are provided for reducing the pressure of the steam supplied to the steam delivery pipes and for eliminating the water condensation which is produced by the reduction in steam pressure..

In the apparatus illustrated herein steam is supplied from the boiler through a pipe 24 to a reducing valve 25 where its pressure is reduced, for example, to five pounds pressure, and passes thence through a pipe 26l through a suitable eliminator 2l, thence through a pipe 28 having therein a shut-off valve 29 to the passage IS which communicates with the steamdelivery pipes I8.

vSuch steam as is not projected from the delivery pipes and any water condensation thereof passing from the opposite end of the passage I6 may be discharged through a valved pipe 30.

The high pressure steam for the heating pipes I9 is supplied through a suitable pipe 3l having a valve 32 to the passage l1 in the header. preferably at the opposite end from that in which low pressure steam is supplied, and passes therefrom into the several heating pipes I9 and is discharged from the opposite endvof the header which is adjacent to the inlet for the low pressure steam through a pipe 33 to a suitable steam trap 34 and thence through a return pipe 35 to the boiler.

It will be understood that the respective conduits I6 and l1 of each of the headers are similarly suppliedI with low pressure and high pressure steam.

By reason of the -construction above described the web of fabric is continuously enveloped in the steam as it passes through the steam chamber. The low pressure steam which is supplied to the passage 6 is projected downwardly 'in' a streamlined path upon the upper surface which contains the more dense fibres of the sheet, thereby causing the surface zone to absorb vaporized moisture from the steam. Condensation in the owing stream of steam is. prevented by the 4contact of the steam with the heating pipes and also with the heat radiating bars which connect the heating and steam delivery pipes. The heat also supplied by the heating pipes serves to prevent condensationv ofany considerable amount of moisture within the heating chamber, thereby avoiding unequal absorption of moisture by any portion of the sheet as it passes through the steam chamber. Y

By reason of the present invention the paperboard sheet is properly conditioned to be acted upon by the rolls which impress thin lines into the surfacefzone of the sheet having the thicker fibre. so that the fibres will not be severed or broken by the action of the thin blades to impress the lines in the sheet, so that when the sheet is severed into sections of suitable length and dried the thickened or outer surfacezone of the sheet may be bent into tubular form Without rupturing the fibres of the surface zone.

The action of the steam upon the printed portions of the sheet serves not only to cause the ink to penetrate the surface zone of the s lieet but also dries it sufficiently so that when the prin'ted lines are impressed into the sheet the ink will not be removed by the blades of the impression roller. By thus impressing into the sheet printed vlines of a selectedcolor which will be descriptive of the contents of the container all danger of such so that the person using the container may readily identify the proper container or a particular product when packing the same, and also readily identify it from any position of observation after the container has been loaded or packed, and even though the container has been subjected to such usage as would remove or destroy such features of the design as are printed upon the l smooth surfaces of the sheet. f

J bodies for knockdown containers from a flat sheet l Having thus described the invention, what is claimed as new, and kdesired to be secured by Letters Patent is:

l. Steps in the method of forming collapsible `of suitable fibreboard which comprises moving the sheet lengthwise, projecting upon one surface of said sheet throughout its width a streamline current cp low pressure steam flowing in the directi'on of movement of the sheet, supplying dry heat at a higher temperature directly and locally to said flowing stream of low pressure steam -to superheat it and prevent condensationthereof and to cause uniform'impregnation by dry steam of the surface zone of the sheet upon which said current is projected and simultaneously indenting suitably spaced transverse thin parallel lines into the surface of said sheet within and while sub jcotcdto said flowing current of steam thereby v' preventing breakage of the fibres of the surface vzone of said sheet and rendering it flexible when 2. Steps in the method of forming collapsible bodies for knockdown containers from a flat sheet of suitable fibreboard which comprises moving the sheet lengthwise through a surrounding volume of steam, projecting upon one surface of said sheet throughout its width a uniform streamline current of low pressure steam flowing in the di- 40 rect-ion of movement of thesheet, supplying dry spaced transverse thin parallel lines into the surume of steam, projectingzupo'n one surface of face zone of said sheet within and'while subjected to said flowing current ofsteam, thereby preventing breakage 0f the fibres of said surface Zone and rendering it flexible when dry.

3. Steps in the method of forming collapsible bodies for knockdown containers from a flat sheet of suitable fibreboad which comprises moving the sheet lengthwise through a surrounding volsaid sheet throughout its width a plurality of uniform streamline currents of low pressure steam fle-wing in thedirection of movements of said sheet and-following said sheet when merging thereupon, suppiying dry heat at a higher temperature directly and locally to each flowing steam of low pressure steam throughout its width to prevent condensation thereof and to cause uniform greater impregnation by dry steam of th: surface Zone upon which said cur-rents are l5 parallel lines in the surface of said sheet withink projected than the impregnation' of the opposite side of said sheet by absorption of moisture from sa'd surrounding volume of steam, and simultaneously indenting suitably spaced transverse and while subjected to the merged streamline currents of steam.

4. The method of forming collapsible bodies for.

tubular knockdown containers from a sheet sof suitable paperboard which comprises causing the sheet of paperboard progressively to pass lengthwise through a surrounding volume of steam thereby to moisten and soften the surface zones of the sheet with moisture and render them pliable, then indenting into .successive sectionsof the' moistened sheet without breaking the fibres thereof thin parallel lines with the spacing of the lines in each section gradually increasing in width through one-quarter of said section, then correspondingly decreasing in width in the next quarter section, then correspondingly increasing in width f in the next quarter section, and correspondingly decreasing in width in the last quarter section,

severing the successive sections from the sheet,

and securing together in overlapped relation the narrow end panels of the sections defined by the lines adjacent the respective ends ofthe section.

5. The method of forming cylindrical collapsible bodies for tubular knockdown containers for flavored ice cream from a sheet of paperboard and providing non-obliterable means for identifying the flavor or character of the contents of the container which comprises printing a design upon the sheet including suitably spaced narrow parallel transverse lines of a predetermined color adapted to identify the contents of the container, progressively passing the printed sheet lengthwise through a surrounding volume of steamI thereby to soften the surface zones ofthe sheet and render them pliable, then indenting portions of said'printed lines into the moistened sheet, thereby to render the sheet flexible when dry and to prevent the printing of the indented portions of the line from obliteration, cutting the sheets into sections of suitable length and securing together overlapped end portions of each section to provide a liquid-tight joint. 3

6. The lmethod of forming collapsible bodies vfor tubular knockdown containers from a sheet of suitable paperboard which comprises passing the sheet lengthwise 'through a surrounding volume of substantially dry steam, causing a current of said steam to move in a streamlined path in the direction of movement of the sheet and in contact with the surface zone of the sheet, supplying heat to said current of steam to prevent premature condensation prior to its contact with the sheet, thereby to moisten and soften said surface zone and render it pliable, then indenting into successive sections of the moistened sheet without breaking the fibres thereof thin parallel l lines with the spacing of the lines in each section gradually increasing in width through one- 'quarter of said. section, then correspondingly decreasing in width in the next quarter section, then correspondingly increasing in width in the l next quarter section, and correspondingly dechamber spaced from the sheet and having means for projecting a. substantially uniform current of steam throughout the width of said sheet in a streamlined path against the surface of said sheet in the direction of movement of the sheet, means for supplying low pressure steam to said steam delivery pipes, means for preheating said low pressure steam to render it dry when projected from said delivery pipes, metal heatingpipes ex-y tending transversely across said steam chamber in parallelism with and in proximity to said steam delivery pipes so located in the path of the current of steam projected from said steam delivery pipes to aid in streamlining the current of steam along the moving sheet, and means for supplying high pressure steam. to said heating pipes thereby to superheat the streamlined current of steam-and prevent condensation thereof before impingement of the steam upon the sheet.

8. Apparatus for use in forming collapsible bodies for tubular containers for ice cream from a sheet of paperboard having non-obliterable means' for identifying the contents of the containers comprising means for printing `uponthe surface of the sheet a design comprising parallel suitably spaced lines of the color adapted to iden,- tify the contents .of the container, means for passing the printed sheet lengthwise through an insulated chamber, enclosing a predetermined portion of the moving sheet, having an entrance and exit opening, steam delivery pipes extending horizontally across said chamber spaced from said sheet having means for projecting a substan.v tially uniform current of steam from said steam delivery pipes throughout thewidth of said sheet is a streamlined path against the surface of the sheet in the direction of movement of the sheet, means for supplying low pressure' dry steam to said steam pipe, means for heating the currents of steam in said chamber, and means located in proximity to the exit from Vsaid chamber for indenting the printed lines into the moistened surface of said sheet.

9. Apparatus for use in forming collapsible bodies for tubular' containers from a flat sheet of suitable breboard comprising a steam vcham-- ber having at its opposite ends parallel narrow entrance and exit slots for the flbreboard sheet,

said surface zone during the continued impreg' nation of moisture therein from said following through, means within said chamber for pro, jecting a streamline current of low pressure steam upon the surface o f said sheet throughout its width in a streamline path in the direction of movement of the sheet to impregnate the fibres of the surface zone thereof with moisture in vaporing the continued impregnation of moisture. therein from said following steam current, and

means within said chamber for supplying directly and locally to the current of low pressure steam throughout its width dry heat at a higher temperature to superheat said current and tov prevent condensation of said low pressure steam, thereby insuring impregnation of said surface zone uniformly by vaporized moisture. v

11. Apparatus for use in forming collapsible bodies for tubular containers from a fiat sheet of suitable breboard comprising a steam chamber having at its opposite ends parallel narrow entrance and exit slots for the fibreboard sheet, means for passing the sheet-lengthwise therethrough, a plurality of steam delivery pipes extending transversely across said chamber spaced from said moving sheet and from each other having means for projecting successively uniform currents of low pressure dry steam in streamline paths throughout the Width 'of said sheet against one surface of the sheet in the direction of movement of the sheet to moisten said sheet and to cause the merging currents to follow said surface from and beyond the exit slot in said chamber, means for supplying dry low pressure steam to said steam delivery pipes, transverse heat-radiating pipes for high pressure steam intermediate of the respective steam delivery pipes and said sheet so positioned in the path of the respective currents as directly to heat said currents and aid in directing them in streamline paths, means for supplying high pressure steam to ,said heat radiating pipes, and means located in the eld of the current of steam following the sheet from said exit slot for indenting transverse parallel thin lines into said moving sheet within and While subjected to the moisture of said following steam current.

l2. Apparatus for use in forming collapsible bodies for tubular containers from a flat sheet of suitable iibreboard comprising a steam chamber having at its opposite ends parallel narrow entrance and exit slots for the fibreboard sheet, means for passing the sheet lengthwise therethrough, a plurality of steam delivery pipesextending transversely across said chamber spaced from said moving sheet and from each other having means for prjecting successively uniform' currents of low pressure dry steam in streamline paths throughout th' width of said sheet against one surface of the sheet 1n the direction of movement of the sheet to moisten said sheet and to cause the merging currents'to follow said surface from and beyond the exit slot in said chamber, means for supplying dry low pressure steam to said steam delivery pipes, transverse heatradiating pipes for high pressure steam intermediate of the respective steam delivery pipes and said sheet, metal bars welded to and connecting said steam delivery pipes and said heat radiating pipes throughout' their length presenting heat radiating surfaces so positioned in the path of the respective currents as directly 'to heat said currents and aid in directing them in streamline paths, means for supplying high pressure steam to said heat radiating pipes, and means located in the eld of the current of steam following the sheet from said exit slot for indenting transverse parallel thin lines into said moving sheet -within and while subjected to I.the moisture of said following steam current.

13. Apparatus for use in formingcollapsible bodies for tubular containers from a flat sheet of suitable ibreboard comprising a steam chamber having at its opposite ends parallel narrow entrance and exit slots for the sheet, means for passing the sheet lengthwise therethrough, suitably spaced parallel headers for low and high pressure steam within said chamber extending lengthwise thereof, spaced-transverse steam delivery pipes communicating at their ends with the 'headers for lthe low pressure steam spaced from thepath of the sheet and provided with apertures for projecting said low pressure steam upon the upper surface ofv the sheet throughout its width in a streamline path in the direction of movementy of said sheet, means for supplying low pressure steam to the low pressure steam headers adjacent to the exit slot of said chamber, means for delivering said low pressure steam freely from the opposite end of said header,l f.

means for eliminating -condensed moisture from .said low pressure steam before its entrance into said headers, parallel transverse heat radiating pipes communicating at their ends with said high pressure headers located adjacent to and I 

